Target insects are rapidly developing resistance to the insecticides which are presently available. Resistance to insecticides in arthropods is widespread, with at least 400 species exhibiting resistance to one or more insecticides. The development of resistance to older insecticides, such as DDT, the carbamates, and the organophosphates, is well documented (see Brattsten, et al. (1986), Science, 231:1255). Resistance to synthetic insecticides has developed extremely rapidly, including the development of resistance to the newer pyrethroid insecticides (see Pickett (1988), Chem. Britain, 137). Therefore, new insecticides are in demand.
Fermentation product A83543, a family of related compounds produced by Saccharopolyspora spinosa, was recently discovered and was shown to exhibit excellent insecticidal activity. A83543 and each of the compounds are useful for the control of mites and insects, particularly Lepidoptera and Diptera species.
By "A83543 compounds" is meant components consisting of a 5,6,5-tricylic ring system, fused to a 12-membered macrocyclic lactone, a neutral sugar and an amino sugar (see Kirst et al. (1991), Tetrahedron Letters, 32:4839). The family of natural components of A83543 include a genus taught in EPO Application No. 0375316 and having the following general formula: ##STR1## wherein R.sup.1 is H or a group selected from ##STR2## and R.sup.2, R.sup.4, R.sub.3, R.sup.5 and R.sup.6 are hydrogen or methyl; or an acid addition salt thereof when R.sup.1 is other than hydrogen.
The family of compounds from A83543 fermentation product has been shown to comprise individual components A83543A, A83543B, A83543C, A83543D, A83543E, A83543F, A83543G, A83543H and A83543J (see European Patent Publication No. O 375 316); and individual components A83543L, A83543M and A83543N (see copending U.S. patent application No. 07/790,287, filed Nov. 8, 1991). The structures of these individual components are shown below. ##STR3## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are for each component as follows:
______________________________________ Structures of A83543 Components Component R.sup.1 R.sup.2 R.sup.3 R.sup.4 R.sup.5 R.sup.6 ______________________________________ A (a) Me H Et Me Me B (b) Me H Et Me Me C (c) Me H Et Me Me D (a) Me Me Et Me Me E (a) Me H Me Me Me F (a) H H Et Me Me G (d) Me H Et Me Me H (a) Me H Et H Me J (a) Me H Et Me H L (a) Me Me Et Me H M (b) Me H Et Me H N (b) Me Me Et Me H PsaA1 H Me H Me Me Me PsaD1 H Me Me Me Me Me PsaE1 H Me H Me Me Me PsaF1 H H H Me Me Me PsaH1 H Me H Me H Me PsaJ1 H Me H Me Me H PsaL1 H Me Me Me Me H ______________________________________